Screen plate



Dec. 26, 1933 E HUTCHENS 1,940,952

SCREEN PLATE Filed April 15. 19:52

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Patented Dec. 26, 1933 PATENT oFF-ics SCREEN PLATE Edward Hutchens, vCu Utility Manufacturing dahy, Wis., assgnor to Company, Cudahy, Wis.,

a corporation of Wisconsin y Application April 13, 1932. Serial No. 604,895

2 Claims. (Cl. 21o- 169) This invention relates to screen plates of the type utilized extensively in lters for Sewage disposal plants, paper mills, yeast plants, breweries Y and the like, and the method of making such plates. j

An object of this inventionv is the provision of an improved screen plate adapted for filtering purposes, and which may be handled without causing injury to the hands by sharp edges and which when brushed Awill' not rapidly cut away and destroy the brushes as has been the disadvantage of screen plates of the prior art.

Another object is the provision of a screen plate designed so that the least resistance. is offered to the screening operation with a screen plate having slots with a given area of clear slot opening.

l A further object is the provision of a novel l method of forming screen plates, resulting in the improved product hereafter set forth in detail.

' Other objects and advantages will .become apparent to those skilled in the art from the following detailed description with reference to the accompanying drawing:

On the drawing:

Figure 1 is a top plan view of a fragment of a screen plate illustrating my invention.

Figure 2 is a bottom plan of that shown in Figure l. Y

Figure 3 is a long of that shown in Figure III- III of Figure 1.

Figure 4 is an enlarge ment of that shown in Figure l and t line IV-IV of Figure 1.

As shown on the drawing:

The embodiment of my'invention herein illustrated comprises a Sheet of metal 3 having a top Surface 4 and a bottom surface 5. A multiplicity of slots 6 preferably in staggered relation or cut 3i)V itudinal section of a fragment l and taken on the line d cross section of a frag'- aken on the in the top of the sheet of metal preferably of ze, copper, zinc, lead or aluminum.

have vertical sides 7, and upwardly and outwardly flared or beveled ends 9 such that the Surfaces 9'of the metal bounding the ends of the slots form obtuse angles with the top surface 4 of the plate.

From the reverse or bottom side of the plate a multiplicity of slots 11 are formed which are preferably wider than the Slots 6 and have curved lateral edges 12, the ends of which are also curved at 13 and beveled in a manner such that the Surface 13 forms an obtuse angle with the bottom surface 5 of the plate.

The slots 11 as illustra brass, bron The slots 6 ted are longer and Wider adjacent the bottom surface of the plate, than are the slots 6 adjacent the top surface of the plate. This construction reduces the resistance to the screening operation for slots having a given clear area of opening. The clear area of opening which is in a plane parallel with the top and bottom surfaces of the plate and intermediate thereof is clearly illustrated in Figure 3. This clear area is smaller than the area of the slot 6 at the top surface of a plate and smal of the slot at the bottom Surface of the plate.

ler than the area My improved screen plate formed by my imy,

proved methodv results 1n a plate eliminating all sharp edges of metal adjacent the top and bottom surfaces of the plate be handled with safety and may be brushed for cleaning the slots,rwithout having a Vdestructive effect on the cleaning brushes as was'the case with the plates f so that the plate may 7 ormed by the method of the A prior art, leaving chisel edges on one side of the plate. In applicants construction as herein illustrated the beveled ends of the slots at the top and bottom of the sheet meet in a plane sub stantially spaced from the top and bottom surfaces of the plate and are sufficiently concealed that the edges 15 do not cause deterioration or rapid wearing away of the cleaning brushes.

Although I have illustrated in the drawing'relatively wide slots instaggered relation, it is within the sphere of my invention to form slots as small as a few thousandths of an inch and to form them in'any desired relation to each other, either staggered or otherwise, and it is not necessary that the slots should be parallel as herein shown. Also Y it is not essential that the slots be formed of the exact relative shape and dimensions or that lthe sides'thereof be of the exact contour herein illustrated. lIt will be appreciated'by those skilled in the art that although I have herein illustrated only one form of my invention, various forms and modifications may be made witho from the principle of my invention, and I desire that the patent to be granted hereon shall not be restricted inany mannerexcept as necessitated by the prior art. f

I claim as my invention:

1. A screen plate of the character described comprising a body of sheet metal having a plurality of slots therethrough, the side walls of these slots from one surface of the plate to a point substantially beneath the surface defining planes normal to the plate surfaces, the lateral walls of the slots adjacent the other'surface of the plate defining curved surfaces, the innermost ut departing parallel n edges of the curved surfaces lying respectively in the planes of the side Walls.

2. A screen plate of the character described comprising a body of sheet metal having aplurality of slots therethrough, the longitudinal Walls of the slots each having a plain surface portion ex- 

